The question of whether patients with celiac disease and dermatitis herpetiformis can safely eat oats has been debated for decades. Oat proteins are not the same as those in wheat, barley and rye. Even so, oats were believed to have toxic effects in people with autoimmune responses to those grains, and most physicians advised their patients to avoid them.

Now, some of the large celiac disease societies and medical centers are advising that limited amounts of oats are probably safe, and even beneficial, for most patients with celiac disease. What changed?

"Pure," Uncontaminated Oats Have Come on the Market

Cross-contamination was a major reason why oats were considered unsafe in the past. Oats, wheat and barley are usually grown next to each other in the fields, processed in the same grain elevators, milled with the same equipment, and transported using the same containers. Inevitably, the grains co-mingle and the oats become contaminated with gluten.

Today, some growers are dedicating fields and equipment to producing oats alone. It has finally become possible to obtain pure oats, free of cross-contamination, from specialized vendors.

Pure Oats May Be Safe for Most, But Not All, Patients

More important in the movement to allow oats in the gluten-free diet has been the increasing amount of research on this topic. Scientists in the United States and Europe have been looking at what happens when patients with celiac disease eat pure, uncontaminated oats.

In numerous studies with adults and children, the majority of patients with celiac disease could tolerate limited amounts of oats. When consumed in moderation (generally no more than about half to three quarters of a cup of dry rolled oats per day for adults, a quarter of a cup per day for children), oats did not cause abdominal symptoms or prevent intestinal healing in most cases.

A small number of people with celiac disease, however, could not tolerate even pure, uncontaminated oats. In these individuals, a protein in oats called avenin triggered an immune response similar to gluten. There was no way to tell in advance which patients would be sensitive to avenins.

What Do Most Experts Recommend?

Most of the large celiac societies and clinical treatment centers now advise patients with celiac disease to consider adding limited amounts of pure, uncontaminated oats to their diet under a doctor's supervision. They point out that oats can provide nutrients, fiber, and diversity to a celiac patient's diet. Newly diagnosed patients, however, are advised not to eat oats until their celiac disease is well controlled (that is, their symptoms have gone away and their blood test results are normal). In all cases, patients who add oats to their diet are advised to see their doctors three to six months later. Furthermore, celiac patients should not eat any products that contain oats unless the oats are clearly labeled as pure, uncontaminated, and gluten-free.

Following are summaries of recommendations from North American organizations and medical centers. To read the full statements, follow the links to each group's website.

• Canadian Celiac Association
  Clinical evidence confirms that consumption of pure, uncontaminated oats is safe in [limited amounts for adults and] children with celiac disease....Individuals... who...add oats or oat products to their diet must ensure that the oats...are free from gluten contamination....A small number of individuals with celiac disease may not tolerate even pure, uncontaminated oats. To ensure that persons with celiac disease are not intolerant to pure and uncontaminated oats, proper clinical follow up with the physician is advised when introducing oats to a gluten-free diet.
• National Foundation for Celiac Awareness
  We advise those with celiac disease to consider adding oats to their diet....Multiple studies show that the majority of patients with celiac disease tolerate oats....[but some] patients may have a sensitivity to the protein portion of oats and develop intestinal inflammation and villous atrophy. This is very rare....We recommend the use of oats only after you have stabilized on the gluten-free diet. This would typically involve blood tests for celiac antibodies becoming negative, and may involve a follow-up biopsy. While on the diet, patients should be monitored with celiac serologic-blood tests.
• Celiac Sprue Association
  Studies continue with mixed conclusions on...whether the consumption of oats evokes an immune response in those with celiac disease and dermatitis herpetiformis. Until it can be determined if the responses that occur are due to cross-contamination in commercially processed oats, to the protein structure of the grain or to other individual differences...excluding oats is the only risk free choice for those on a gluten-free diet.
• Celiac Center at Beth Israel Deaconess Medical Center
  Based on numerous studies conducted with adults and children in Europe and the United States, it appears that the majority of individuals with [celiac disease] can tolerate oats....[C]lose monitoring by a healthcare professional experienced in celiac disease is recommended during introduction of oats into a gluten free diet....[N]ewly diagnosed patients [are advised to avoid oats] until it can be clearly demonstrated that celiac disease is well-controlled.....Follow-up with the patient's gastroenterologist should occur three to six months after the addition of oats into the gluten-free diet.
• University of Chicago Celiac Disease Center
  Regular, commercially available oats are frequently contaminated with wheat or barley. However....pure, uncontaminated oats can be consumed safely in [limited] quantities....It is important that you talk to your physician and your registered dietitian prior to starting oats.
• Celiac Disease Center at Columbia University
  The proteins of oats are not toxic to individuals with celiac disease. There are multiple studies from both Europe and the USA demonstrating the safety of oats for patients with celiac disease and dermatitis herpetiformis...The only concern with oats is whether they are contaminated with wheat, barley or rye. Patients with celiac disease attending the [Celiac Disease Center at Columbia University] are advised that they can consume oats.